I just upgraded to V4 Pro and all of my 464 VST plugs have failed the scan. I reset the blacklist several times with he same out come. No problems with Samplitude, Reaper, Cubase or FL Studio. Did restart to no avail. Any help appreciated. Am posting to support as well.

No JBridge involved. The log file is here: C:\Users\xxxx\AppData\Roaming\PreSonus\Studio One 4\x64 I will post it soon

As mentioned early start with no paths and slowly work up by adding one path at a time.

Yes I tried that already and they still failed. Everything fails. I have a session at 6pm and I wanted to use S1. I guess I'll have to stick with the Presonus native plugs until a solution is found. Interestingly if I copy the VST plug-ins settings file from V3 to V4 some of the plug-ins appear in V4 but the scan still continues to fail.

The only reason some of them were working was because I copied the plug-in list from the version 3 installation. But they are only VST3 versions. But if I start afresh all of the plug-ins fail when scanning. This forum won't allow me to upload a text file of the list of blacklisted plug-ins. Although I've added it to my support ticket.

jpettit wroteThat is what I meant by pattern. VST3 but not VST2. The article talks about iLok plugins etc. The log should also give you a hint.

To reduce the count I removed all VST2 that were redundant with a VST3.

I also launched a campaign of removing all VST2 that had a VST 3 version available not really too big of a deal because they were hidden in my plugin menu anyway. Another reason for this was that along the way I found that If I went into the settings and disabled VST 2.4 support my system worked. The part I failed to mention was that in addition to the problem discussed here my sessions would also crash randomly during saves and always during “restore version.” It all seemed related to my system failing to scan those plugins I mentioned.

Presonus went through my logs, crash reports pretty much everything you can imagine and nothing made sense to them.

In the end this was the only thing that worked. But it has repeated at least once more but the same fix was effective.

This is just one example but all 444 plugs have the same message. Incidentally the scan took around 2 hours.Also I removed my VST2 folder from the program files location and put it on the desktop. I also disabled VST2 support in the S1 service. I then pointed the studio one plug-in directory common files> VST3 and scanning then failed completely. Obviously there is some kind of weird problem based on my configuration as not everyone has it. But I can say that this is a recent new build computer and a fresh Windows 10 install. In all my years of using DAW's I've never come across this problem before. It's very discouraging.

Had this happen on my machine I use for testing. It had worked previously and one day it failed scanning. Turned out my firewall (Zonealarm Free) blocked the plugin scanner. Not sure how it happened but after resetting the permissions for the plugin scanner it worked.

Have you verified your paths in "Options/Locations" (at the top menu)?So to troubleshoot a dead Faderport, I renamed the S1 'Settings' file.It's located here: C:\Users\xxxx\AppData\Roaming\PreSonus\Studio One 4...

When S1 v4 restarts, it rebuilds (from what/where I'm not sure) the "Settings" file.So then, when I loaded a song it was missing lots of plugins because the paths weren't there any longer. I just had to re-add all my paths where the plugins exhist and I eventually got them all in there.

Thank you everyone for your contributions to this thread it's much appreciated. I also had several communications with the Presonus support over the last couple of days. Unfortunately none of the suggestions here or from support worked. So basically what I did was what they call a Windows 10 reset which takes the installation back to when it was first installed more or less. I re-installed all my plug-ins, well most of them so far. Then installed Studio One V4 and miracle of miracles all the plug-ins scanned immediately without any problems. So I've no idea what was causing the problem because I only did my last Windows 10 clean install couple of months ago when I replaced the motherboard CPU and memory. But it's a big relief that I finally got the plug-ins scanned.